Add some support for the code-point code-unit distinction.

runtime/vm/intermediate_language.cc

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/intermediate_language.h"
 
 #include "vm/bit_vector.h"
 #include "vm/dart_entry.h"
 #include "vm/flow_graph_allocator.h"
 #include "vm/flow_graph_builder.h"
@@ skipping 201 matching lines @@
   }
   UNREACHABLE();
   return NULL;
 }
 
 
 static bool CompareNames(const Library& lib,
                          const char* test_name,
                          const String& name) {
   // If both names are private mangle test_name before comparison.
-  if ((name.CharAt(0) == '_') && (test_name[0] == '_')) {
+  if ((name.CodeUnitAt(0) == '_') && (test_name[0] == '_')) {
     const String& test_name_symbol = String::Handle(Symbols::New(test_name));
     return String::Handle(lib.PrivateName(test_name_symbol)).Equals(name);
   }
   return name.Equals(test_name);
 }
 
 
 MethodRecognizer::Kind MethodRecognizer::RecognizeKind(
     const Function& function) {
   // Only core and math library methods can be recognized.
@@ skipping 2413 matching lines @@
       return Array::length_offset();
     default:
       UNREACHABLE();
       return -1;
   }
 }
 
 #undef __
 
 }  // namespace dart